Things brightened up, however, when he was traded to the Royals on July 20, 2012, and came under the guidance of pitching coach Dave Eiland, who had seen a lot of Guthrie in his Baltimore years when he was pitching coach of the American League East-rival Yankees.

"He was a guy who didn't always get the results that he should've gotten. He pitched up in the zone," Eiland said.

When Guthrie was obtained in exchange for pitcher Jonathan Sanchez, Eiland looked at Guthrie's Colorado video footage and found that things hadn't changed much. So when Guthrie reported to the Royals, Eiland had a talk with him.

"I've got a couple little things, but I want to see you pitch a game or two first," Eiland told him and then watched him lose to Minnesota and Seattle. "After that game in Seattle, I said, 'You ready to go?' and he said, 'Yeah.' So we went in the bullpen and made some adjustments."

Eiland adjusted Guthrie's shoulder tuck, changed his foot on the rubber, moved his hands down, worked on his balance.

"All that was designed to get him down in the zone and add a little deception," Eiland said. "He bought into it right away and worked on it hard, and continues to work on it to this day every day."

Guthrie also lost his third start for the Royals to Texas, but felt improvement. Since then, he has made 17 consecutive starts without a loss, a club record. The team has gone 15-2 in those games and Guthrie's personal record is 9-0 with a 2.25 ERA.

Guthrie's 2-0 win over the White Sox on Saturday was his first big league shutout in 189 starts. He's tossed 16 2/3 consecutive scoreless innings going into Thursday night's start at Baltimore.

"Now he's down in the zone and when he misses, he misses down," Eiland said. "Pitching from thigh to belt-high like he used to, when he missed he missed up. Now when he's from thigh down, his misses are down.

"And he gained some confidence. And once a guy with that pitchability gains some confidence, this is what happens."

Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.